1. Field of the Invention
The invention relates generally to an apparatus for converting solar energy into a usable energy product and, more particularly, to an economical system for harnessing the sun's energy, storing this energy and/or converting this energy into a mechanical and/or electrical energy product on a sustainable cycle.
2. Description of Related Art
Solar energy has been available as a source of power for more than 4.5 billion years. For centuries, inventors have been devising various means to harness this energy. As far back as the third century B.C., records indicate that the Greek and Roman armies used “burning mirrors” to focus sunlight as weapons of war to ignite fires and to burn sails of enemy warships.
Solar energy provides the world either directly or indirectly with the majority of its energy. Solar energy is a renewable energy source having vast potential. Although solar energy is abundant, a major drawback is that it is diffuse and not available at all hours. Solar energy can be affected by the time of the day, the seasons, and the changing sun path in the sky as the earth's axis is not at a right angle to the sun but it is tilted away at an angle of 23.5°.
For decades, inventors have tried various systems for harnessing this incredible energy source. For example, U.S. Pat. Nos. 3,988,166; 4,286,581; 5,275,149 and 4,038,971 have sought to control and convert this energy into a cost-effective usable form. Unfortunately, these systems are cumbersome, expensive to manufacture and maintain, expensive to operate and yield little in terms of usable, convertible energy.
The article entitled “Principles of Solar Thermal Conversion” by R. H. B. Exell, 2000. King Mongkut's University of Technology Thonburi also discusses academic interest only, of trapping solar radiation in an enclosed volume with perfectly reflecting walls at the temperature of the sun, i.e., approximately 5800K and the need for a parabolic concentrator that focuses direct solar radiation into the enclosed volume. The article further discusses that if solar energy were to be used on a large scale, since solar energy is theoretically a very high temperature resource, one should try to harness it at this very high temperature for efficient conversion and then use the waste heat for low temperature purposes instead of downgrading the solar energy with low temperature collectors at the start. This article recites a theory for what is desired in this technology, but provides no direction as to how it can be achieved.
U.S. Pat. No. 7,640,931 to Tarabishi (hereinafter, “the '931 patent”), the entirety thereof being incorporated by reference thereto, is directed to a solar collecting system which can concentrate or condense solar energy at a fixed, stationary focal point to economically harness the sun's energy into a manageable and convertible form as desired in the Exell article. In particular, the '931 patent teaches a system for tracking the sun and maintaining a constant fixed focal point or sub-focal point to at least partially condense the sun's rays into a high-energy beam that can be redirected to a predetermined location for generating electrical power, heat energy, steam, and the like.
PVC panels currently in use are costly, have low efficiency, and only work while the sun is shining Even if a large cloud passes over the PVC field for only a few minutes, a significant megawatt loss of power can occur.
The Solar Stirling system consists of a series of mirrors in the form of a collector panel that concentrates the sunlight at a focal point which is moving in space following the east-west movement of the collector panel. A piston generator is also mounted/suspended in space in relation to the collector panel. However, due to its location in space, it is limited in size and thus has limited power output, along the lines of around 24 KW. This system is inefficient, i.e., around 25-30%, and is unable to convert a high amount of energy because the focal point is not stationary and the generator is only able to process a small amount of the condensed solar energy received.
However, as acknowledged by the Exell article, and as discussed above, a need still exists for capturing, converting and storing this solar energy in a sustainable format so that a constant energy supply is available. Current thermal energy storage systems are weak and not able to meet the significant demand during sunless hours. Storing thermal energy is a crucial issue in achieving sustainable energy. The cost related to commercially large scale electric power generation from the sun as the source, and the subsequent need for transmission, are prohibitive and limited. Leading existing solar collecting companies require a large amount of land to install a huge number of mirror arrays, thousands of PVC panels, or sun catcher systems. All of these systems require thousands of acres to achieve a meaningful industrial electric power output and have a low efficiency, between about 15-30% conversion of the energy received.
The present invention provides a low cost alternative solar energy conversion in regard to the conversion systems currently in use, is highly efficient in that it achieves almost 100% conversion of the solar energy into a usable format, and provides a sustainable storage and energy supply. The efficiency of the present invention can also be increased through the use of multiple integrated units. Further still, the system of the present invention is essentially pollution-free, leaving an essentially zero carbon footprint. Additionally, the system of the present invention is compact in size compared to the systems currently in use and, consequently, can be assembled at almost any location, i.e., inland, shoreland, and the like, as less land is used and it eliminates the need for devices to transmit the energy, such as cables and the like, to a separate location for conversion into a usable energy product. Also, the system of the present invention can generate a sustainable high power output during both sunny hours and sunless hours due to its unique, yet simple design and its inherent features and benefits.